That's a good score! Thanks for posting it and I'm glad you like the game. You're right about the UFO's too, they're key to getting high scores.
For anyone reading this who doesn't know the trick to the UFO's here's how it works:
Shoot a UFO and the points for the next one will be doubled, up to a set maximum. If a UFO passes the side of the screen without you shooting it, the points for the next UFO will reset to the base amount. So keep shooting the UFO's and not letting them go past the side of the screen and your score can build up very quickly!